Babies’ neurons firing on all cylinders
I just returned from meeting my newest granddaughter, 3 weeks old. Babies don’t know anything. Prior to birth their whole lives have been wet, warm, quiet, almost weightless and dark. Then suddenly everything changes. Things start to get tight. They’re being pushed around. Their blood pressure goes up and their heart beat slows. This is work!
Next it’s cold air, bright lights, air in their lungs, and then someone slaps them on the behind. What is going on?
That last question, if my granddaughter could talk, would have originated in the cerebrum. The cerebrum is the very topmost layer of the brain and is only about the thickness of six playing cards. When babies are born, they have about 20 billion neurons in their cerebrum. Each neuron is connected to about a thousand other neurons creating a complex, 3-dimensional net of interconnected cells.
This thin layer is the area of the brain where we experience our conscious thoughts. Though the baby knows no words, it is surely aware that things have changed.
See the baby reach for its rattle. See the baby miss the rattle. See the baby wave its hand about to try and grasp the rattle. Baby holds the rattle. Baby tries to put the rattle in its mouth. Baby sticks the rattle in its eye. Baby has a lot to learn.
But baby does learn. In about five short years, babies are in major control of their bodies. They can crawl, walk, run, dance and maybe even ride a bike. They can throw, kick and climb. One of their most impressive accomplishments is that they have learned to speak in their native tongue. That doesn’t seem like too big of a deal if they have learned English. Even I can do that. But those little Chinese babies learn Mandarin. That’s impressive.
Do you know what else? They do it all without school. They accomplish these things pretty much by doing the things they want to do, and they manage to learn a tremendous amount in five years. Does that mean I could learn Mandarin if I immersed myself in it for five years? It sort of seems like babies want to learn about their world more than I want to learn Mandarin.
By the age of 10 or 12 years, a child still has most of those 20 billion neurons. What has changed is that each neuron would now have about 10,000 connections. Can we even imagine 20 billion neurons with 10,000 connections each? In this light, learning seems to be the process of growing larger cells, just like building large muscles.
Now, guess what? No one is in charge of making this happen. There is no central neuron telling the other neurons what to do. Learning is just a matter of information coming and going. The baby begins to grow connections between neurons, and the neurons start to talk to one another. Out of that nervous chatter grows intent, control and, eventually, thought. As more and more neurons become interconnected in an amazingly rich maze, the baby begins to understand its world.
For instance, if one neuron becomes associated with the idea of “Mom,” then other neurons may connect with the “Mom neuron” and associate with other ideas like food, warmth and comfort. But the branch line for warmth can connect to yet another neuron that will become associated with blanket. Then blanket can become associated with the “bed neuron,” and so forth.
Learning through these neuron connections is an example of order spontaneously arising from disorder. Humans often think that there can only be order if there is central control. But there are many instances where order can arise from decentralized processes.
In nature it seems that decentralized control is the most common governing force. The human penchant for central control is often what causes environmental problems.
Each time, though, learning begins as a decentralized process with each new baby.
Gary McCallister is professor of biology at Mesa State College.